Pump system and method thereof

ABSTRACT

A pump system includes a plurality of pump assemblies. Each pump assembly having a power assembly and a fluid assembly. Each power assembly of each pump assembly includes a crankshaft, an input connection, and an output connection. The input connection of one pump assembly among the plurality of pump assemblies connected to the output connection of one pump assembly among the plurality of pump assemblies; at least one lead pump assembly within the plurality of pump assemblies configured to be connected to a prime mover commonly driving the plurality of pump assemblies. Also included is a method of pumping pressurized fluid to a site.

BACKGROUND

In the drilling and completion industry, the formation of boreholes for the purpose of production or injection of fluid is common The boreholes are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and alternatively for CO2 sequestration. To increase the production from a borehole, the production zone can be fractured to allow the formation fluids to flow more freely from the formation to the borehole. The fracturing operation includes pumping fluids at high pressure towards the formation to form formation fractures. To retain the fractures in an open condition after fracturing pressure is removed, the fractures must be physically propped open, and therefore the fracturing fluids commonly include solid granular materials, such as sand, generally referred to as proppants. Other components of the fracturing fluids typically include water, gel, or other chemical additives.

The pressure required for hydraulic fracturing of a formation, for example, often requires fracturing fluid to be pumped at pressures of 10,000 to 15,000 psi in order to create a fracture in the formation. To pump the fracturing fluids at the high pressures required for fracturing, crankshaft driven positive displacement pumps are used. The crankshaft driven positive displacement pumps include a fluid end and a power end. The fluid end includes a number of plungers driven by a crankshaft toward and away from a chamber in order to affect a high or low pressure on the chamber. The fluid end receives relatively low pressure fluid, and pressurizes the fluid to provide higher pressurized fracturing fluid at the required pressure for fracturing within the borehole. The power end includes or is attached to a pump powering mechanism also known as a prime mover, commonly an electric motor, which connects to the crankshaft or a pinion shaft to drive the power end.

The art would be receptive to improved apparatus and methods for hydraulic fluid fracturing pumps.

BRIEF DESCRIPTION

A pump system including a plurality of pump assemblies, each pump assembly having a power assembly and a fluid assembly, each power assembly of each pump assembly including a crankshaft, an input connection, and an output connection, the input connection of one pump assembly among the plurality of pump assemblies connected to the output connection of one pump assembly among the plurality of pump assemblies; at least one lead pump assembly within the plurality of pump assemblies configured to be connected to a prime mover commonly driving the plurality of pump assemblies.

A method of pumping pressurized fluid to a site, the method including selecting a prime mover; selecting a number of pump assemblies, each pump assembly having a power assembly and a fluid assembly, each power assembly including a crankshaft, an input connection, and an output connection; arranging the pump assemblies on a surface; connecting the input connection of each pump to an output connection of an adjacent upstream pump; and, connecting at least one lead pump to the prime mover to commonly drive the plurality of pumps.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 shows a perspective view of an exemplary embodiment of a pump system mounted on a trailer bed of a truck;

FIG. 2 shows a side view of an exemplary embodiment of a pump system mounted on a flatbed of a train;

FIG. 3 shows a top view of the exemplary pump system of FIG. 2;

FIG. 4 shows a cross-sectional view of a pump assembly according to the prior art;

FIG. 5 shows a perspective view of two adjacent exemplary pump assemblies usable in the exemplary pump system of FIGS. 1-3;

FIG. 6 shows a perspective view of another exemplary embodiment of a pump assembly usable in the exemplary pump system of FIGS. 1-3;

FIG. 7 shows a cross-sectional view of an exemplary embodiment of a reciprocating pump assembly having two fluid assemblies; and,

FIG. 8 shows a cross-sectional view of another exemplary embodiment of a reciprocating pump assembly having two fluid assemblies.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

With reference to FIG. 1, a pump system 10 is shown mounted on a platform 12, such as at least one trailer bed 14 of a truck 16 for portability. In the illustrated embodiment, two linked trailer beds 14 are employed that are pulled by the truck 16. As shown in FIGS. 2-3, the pump system 10 is alternatively illustrated as mounted upon a flatbed 18 of a train 20 and pulled by a train 20. While FIGS. 1-3 advantageously illustrate a portable pump system 10, it would be within the scope of these embodiments to also provide the pump system 10 on any type of mounting surface or platform 12 including other surfaces designed for portability as well as those designed as a permanent or semi-permanent fixtures.

The pump system 10 further includes or utilizes a prime mover 22, and is particularly designed to take advantage of higher HP prime movers 22. The prime mover 22 could be an electric motor such as a super conducting electric motor or an internal combustion engine such as a turbine engine, or diesel engine, although other prime movers 22 are within the scope of these embodiments. The illustrated prime mover 22 of FIG. 1 is a turbine engine. A radiator 24 is additionally provided for cooling. A gear box 26 is positioned between the prime mover 22 and the remainder of the pump system 10. At least one output shaft 28 extends from the gear box 26 and connects a lead pump assembly 30 of the pump system 10 to the prime mover 22 via the gear box 26. In the illustrated embodiments, two output shafts 28 extend from the gear box 26, although the gear box 26 is not limited to one or two outputs and may alternatively include additional outputs.

Enabled by the output or power rating of the high horsepower prime mover 22, the pump system 10 includes a plurality of pump assemblies 32, at least two of which are arranged end-to-end using connections as will be further described below. Each pump assembly 32 is a positive displacement pump, in particular a reciprocating pump assembly 32 as shown. The pump assembly 32 is usable for a fracturing application in which fracturing fluid, such as, but not limited to a proppant filled slurry, is pumped downhole into a borehole for creating and potentially propping fractures in a formation. While particularly suited for a fracturing application, the pump system 10 may be employed in other applications. Each pump assembly 32 includes a power assembly 34, sometimes referred to as a power end, and a fluid assembly 36, sometimes referred to as a fluid end. The power assembly 34 includes a crankshaft housing 38 which houses a crankshaft as will be further described below. A crosshead assembly 40 is interposed between the power assembly 34 and the fluid assembly 36. The crosshead assembly 40 converts rotational movement within the power assembly 34 into reciprocating movement to actuate internal pistons or plungers of the fluid assembly 36. While the illustrated pump assemblies 32 include five internal pistons to pump the fluid in the fluid assemblies 36, an alternate number of pistons may be provided in each pump assembly 32, or alternatively an alternate number or pistons in different pump assemblies 32.

With reference to FIG. 3, the fluid assembly 36 includes an input valve connected to an inlet 42 and an output valve connected to an outlet 44. The inlets 42 of the pump assemblies 32 are connected to a source of fluid, such as a proppant filled slurry. The outlets 44 of the pump assemblies 32 may be connected to hoses, piping or the like to direct pressurized fluid to a borehole. Withdrawal of a piston during a suction stroke pulls fluid into the fluid assembly 36 through the input valve that is connected to the inlet 42. Subsequently pushed during a power stroke, the piston then forces the fluid under pressure out through the output valve connected to the outlet 44.

An exemplary embodiment of the internal mechanics of a reciprocating pump assembly 100 is shown in FIG. 4. The power assembly 114 includes a crankshaft 134 rotatable about a longitudinal axis 136. The crankshaft 134 includes a plurality of eccentrically arranged crankpins 142 (or alternatively a plurality of eccentric sheaves), and a connecting rod 144 is connected to each crankpin 142. The connecting rods 144 connect the crankpins 142 to the pistons 146 via the crosshead assembly 122. The connecting rods 144 are connected to a crosshead 148 using a wrist pin 150 that allows the connecting rods 144 to pivot with respect to the crosshead 148, which in turn is connected to the pistons 146. The longitudinal axis 152 of each of the pistons 146 is perpendicular to the longitudinal axis (rotational axis) 136 of the crankshaft 134. When the crankshaft 134 turns, the crankpins 142 reciprocate the connecting rods 144. Moved by the connecting rods 144, the crosshead 148 reciprocates inside fixed cylinders. In turn, the pistons 146 coupled to the crosshead 148 also reciprocate between suction and power strokes in the fluid assembly 116. Input valves 154 are connected to the inlet 126 and output valves 156 are connected to the outlet. The fluid assembly 116 includes vertical passages 158 for passing fluid from each of the input valves 154 to respective output valves 156. The fluid assembly 116 also includes horizontal passages 160 that are directed along the longitudinal axis 152 of the pistons 146. The horizontal passages 160 are in fluid communication with the vertical passages 158. Withdrawal of a piston 146 during a suction stroke pulls fluid into the fluid assembly 116 through an input valve 154 that is connected to an inlet 166. Subsequently pushed during a power stroke, a piston 146 then forces the fluid under pressure out through the output valve 156 connected to an outlet 168. Pressure relief valves 162 are further included at a location opposite the pistons 146, at an end of the horizontal passages 160 of the fluid assembly 116, and are employed if a predetermined pressure threshold is reached within the first horizontal passages 160.

The pump assemblies 32 may operate in a similar fashion to the pump assembly 100, except that the crankshafts 48 of adjacent pump assemblies 32 are interconnected as described herein. With reference to FIGS. 1-3, and further reference to FIG. 5, the prime mover 22 drives the pump assemblies 32 via the gear box 26, output shaft(s) 28, and input flanges 50 of the pump assemblies 32. If the pump assemblies 32 are not directly connected to the output shaft 28 of the gear box 26 (that is, if the pump assembly 32 is not a lead pump assembly 30), then the input flange 50 of a downline pump assembly 32 is driven by the output shaft 52 of an upstream adjacent pump assembly 32. The crankshaft 48 can be rotated directly by an input end of the crankshaft 48. Alternatively, the pump assembly 32 can include a pinion shaft (not shown) that engages with the crankshaft 48, and the pinion shaft is rotatable by the prime mover 22 which in turn moves the crankshaft 48. The output shaft 52 may be centered in-line with a rotational axis 54 of the crank shaft 48, may be a portion of the crank shaft 48 that extends exteriorly of the crankshaft housing 38, may be centered in line with a rotational axis of a pinion shaft (not shown) that rotates the crankshaft, or alternatively the output shaft 52 may be otherwise offset from the crankshaft 48. The output shaft can come off the back of the power assembly 34 as shown in FIG. 5, or can come out of a planetary gear box 56 on the pump assembly 32 as shown in FIGS. 2 and 3. In any of the above-described exemplary embodiments, the prime mover 22 is employed to rotate the crankshaft 48 within the crankshaft housing 38 of each respective pump assembly 32.

To connect one pump assembly 32 to an adjacent pump assembly 32, input connections 58 and output connections 60 are employed that are either directly connected to each other as shown in FIGS. 2-3 or connectable by a linking rod 62 as shown in FIG. 5. In an exemplary embodiment, the input connection 58 may be substantially identical to the output connection 60 except that the input connection 58 is attached to the input flange 50 and the output connection 60 is attached to the output shaft 52. In the illustrated embodiment, the input and output connections 58, 60 include plates 64 fixedly connected to the input flange 50 and output shaft 52. If connected by a linking rod 62, the linking rod 62 may also include the plates 64. The plates 64 are illustrated as having a surface that extends substantially perpendicular to an axis of rotation 54 of the crankshaft 48. The plates 64 are shown to include a plurality of apertures 66. When the apertures 66 of face-to-face plates 64 are aligned, a connector can be passed through the apertures such that the input connection 58 is connected to the output connection 60. While apertures and connectors are described for connecting the input and output connections 58, 60, one of the input and output connections 58, 60 may alternatively include protrusions which pass through apertures of the other of the input and output connections 58, 60. Additional protrusions and corresponding indentations for mating the input and output connections 58, 60 and imparting rotation from one to the other are also includable in the input and output connections 58, 60. In an exemplary embodiment, the input connection 58 is also removable from the output connection 60 so as to impart modularity to the pump system 10. Rotation of a crankshaft 48 within a pump assembly 32 rotates the output shaft 52 and the output connection 60, which in turn rotates the input connection 58, which rotates the input flange 50 and the crankshaft 48 of an adjacent pump assembly 32.

The pump system 10 includes at least a first set 70 of two pump assemblies 32 linked end to end. The illustrated embodiments shown in FIGS. 1-3 include a first set 70 of pump assemblies 32 and a second set 72 of pump assemblies 32. Each set 70, 72 of pump assemblies 32 includes a single lead pump assembly 30 that is attached to a respective output shaft 28 of the gear box 26. That is, the first set 70 of pump assemblies 32 includes a first lead pump assembly 30 attached to a first output shaft 28 of the gear box 26, and the second set 72 of pump assemblies 32 includes a second lead pump assembly 30 attached to a second output shaft 28 of the gear box 26. Extending from the first lead pump assembly 30 in the first set 70 is an output shaft 52 engageable with an input flange 50 of a second pump assembly 32 in the first set 70 of pump assemblies 32. Likewise, the second pump assembly 32 is connected to a third pump assembly 32 in the first set 70 of pump assemblies 32, and the second set 72 of pump assemblies 32 includes a second pump assembly 32 and a third pump assembly 32 directly and indirectly connected, respectively, to the second lead pump assembly 30. Thus, in the illustrated embodiment of the pump system 10, six pump assemblies 32 are connected to a single prime mover 22 and the output of the ultra high HP prime mover 22 can be divided between the pump assemblies 32 within the pump system 10. For example, if a prime mover 22 has a horsepower rating of 18,000 HP, then six pump assemblies 32 with a horsepower rating of 3,000 HP could be arranged within the pump system 10. The only restriction to providing the multiple pump assemblies 32 within the pump system 10 would be the weight limitations of each flat bed 18 or trailer bed 14 in the portable system 10 shown in FIGS. 1-3. For example, if the flat bed 18 or trailer bed 14 was rated for 80,000 pounds and each pump assembly weighed 20,000 pounds then only four pump assemblies 32 could be placed on a single flat bed 18 or trailer bed 14. This issue can be remedied by employing additional linked flat beds 18 or trailer beds 14, and providing linking rods 62 as necessary between the input connection 58 and output connection 60 of adjacent pump assemblies 32 provided on adjacent platforms 12.

While the pump assemblies 32 of the pump system 10 have been described to include a power assembly 34 attached to a single fluid assembly 36, an alternative embodiment of a pump assembly 232 may include a power assembly 234 operatively connected to first and second fluid assemblies 236, as shown in FIG. 6. The ability to include a second fluid assembly to a power assembly is described in U.S. patent application Ser. No. 13/687,558 filed on Nov. 28, 2012 entitled “RECIPROCATING PUMP ASSEMBLY AND METHOD THEREOF”, and is herein incorporated by reference in its entirety. With reference to FIG. 6, the first and second fluid assemblies 236 each include an input valve connected to an inlet 242 and an output valve connected to an outlet 244. As with the pump assembly 32, the prime mover 22 is employed to rotate the crankshaft within the crankshaft housing 238 of the pump assembly 232 either directly or via a pinion shaft. FIG. 7 shows an exemplary embodiment of first and second fluid assemblies 236 each operated by a separate crankshaft 48 that are commonly rotated by a pinion shaft 275. The pinion shaft 275 includes at least one pinion gear (not shown) which engages with at least one bull gear (not shown) on each of the first and second crankshafts 48. The pinion shaft 275 is rotated by the prime mover 22 to operate the crankshafts 48. FIG. 8 shows an exemplary embodiment for first and second fluid assemblies 236 to be rotated by a common crankshaft 48 that is rotated by the prime mover 22. It is noted that while only the crosshead assemblies 40 are shown, the fluid assemblies 236 may be the same as in the previous embodiments. Also as in the previous embodiments, with reference again to FIG. 6, the pump assembly 232 includes an input connection 258 and an output connection 260 that enable adjacent pump assemblies 232 or 32 to be directly inter-connected via the connections 258, 260 or by an additional linking rod 62 as previously described. By adding a second fluid assembly 236 to a power assembly 234 of the pump assembly 232, the amount of horsepower that the pump assembly 232 can consume is doubled. The structural improvements to the power assembly 234 to accommodate the first and second fluid assemblies 236 provide a compact design that can assist in arranging multiple pump assemblies 232 and/or 32 on a trailer bed 14 or flat bed 18 for transportation.

In addition to taking advantage of the output of a high horsepower prime mover 22, because each pump assembly 32, 232 includes an input connection 58, 258 and an output connection 60, 260, a modular arrangement of the pump system 10 is enabled to include any number of pump assemblies 32, 232 thereon in a variety of configurations.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. 

What is claimed:
 1. A pump system comprising: a plurality of pump assemblies, each pump assembly having a power assembly and a fluid assembly, each power assembly of each pump assembly including a crankshaft, an input connection, and an output connection, the input connection of one pump assembly among the plurality of pump assemblies connected to the output connection of one pump assembly among the plurality of pump assemblies; at least one lead pump assembly within the plurality of pump assemblies configured to be connected to a prime mover commonly driving the plurality of pump assemblies.
 2. The pump system of claim 1 wherein the plurality of pump assemblies includes a first set of pump assemblies and a second set of pump assemblies, each set of pump assemblies including a lead pump assembly configured to be connected to the prime mover.
 3. The pump system of claim 2 wherein fluid assemblies of the pump assemblies in the first set of pump assemblies are separated from fluid assemblies of the pump assemblies in the second set of pump assemblies by the power assemblies of the pump assemblies in the first and second sets of pump assemblies.
 4. The pump system of claim 2, wherein the first set of pump assemblies is arranged on a first side of a platform, and the second set of pump assemblies is arranged on a second side of the platform opposite the first side.
 5. The pump system of claim 1 further comprising the prime mover, wherein a sum of the horsepower rating of the plurality of pump assemblies is substantially equal to the horsepower rating of the prime mover.
 6. The pump system of claim 1 wherein the fluid assembly of one pump assembly among the plurality of pump assemblies includes a first fluid assembly and a second fluid assembly, the power assembly of the one pump assembly interposed between the first and second fluid assemblies.
 7. The pump system of claim 1 wherein the plurality of pump assemblies are mounted on at least one movable platform.
 8. The pump system of claim 7 wherein the at least one movable platform includes at least one of a trailer bed towable by a truck and a flat bed connected to a train.
 9. The pump system of claim 1 wherein at least a subset of adjacent pump assemblies among the plurality of pump assemblies are connected end-to-end relative to the crankshaft of each pump assembly.
 10. The pump system of claim 1 wherein the input connection of the one pump assembly among the plurality of pump assemblies is removably connected to the output connection of the one pump assembly among the plurality of pump assemblies.
 11. The pump system of claim 1, wherein each of the pump assemblies includes a housing, the input connections and the output connections extending exteriorly of the housing.
 12. The pump system of claim 1, wherein the input connection and the output connection are respectively connected to an input shaft and an output shaft, and an axis of the input shaft and an axis of the output shaft extend substantially parallel to a rotation axis of the crankshaft within each pump assembly among the plurality of pump assemblies.
 13. The pump system of claim 1, wherein the input connection includes an input plate and the output connection includes an output plate, the input plate and output plate arrangeable and configured to connect to each other in a face-to-face relationship.
 14. The pump system of claim 13, wherein at least one of the input and output plates includes at least one aperture, and further comprising at least one connector passing through the at least one aperture.
 15. The pump system of claim 1, further comprising a gear box including at least one output shaft connected to the input connection of the at least one lead pump assembly.
 16. A method of pumping pressurized fluid to a site, the method comprising: selecting a prime mover; selecting a number of pump assemblies, each pump assembly having a power assembly and a fluid assembly, each power assembly including a crankshaft, an input connection, and an output connection; arranging the pump assemblies on a surface; connecting the input connection of each pump to an output connection of an adjacent upstream pump; and, connecting at least one lead pump to the prime mover to commonly drive the plurality of pumps.
 17. The method of claim 16, wherein the prime mover has a power rating and selecting a number of pump assemblies includes selecting a number of pump assemblies having a combined power rating substantially equivalent to the power rating of the prime mover.
 18. The method of claim 16 wherein arranging the pump assemblies on a surface includes arranging the pump assemblies on a movable platform.
 19. The method of claim 16 wherein selecting a number of pump assemblies includes selecting at least three pump assemblies.
 20. The method of claim 16 wherein arranging the pump assemblies includes arranging two sets of at least two pump assemblies, each set including one lead pump assembly connected to the prime mover and at least one additional pump assembly. 